/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xalan.templates;

import javax.xml.transform.TransformerException;

import wx.xml.xalan.xalan.transformer.TransformerImpl;
import wx.xml.xalan.xpath.XPathContext;
import wx.xml.xalan.xpath.objects.XObject;

/**
 * Handles the EXSLT result element within an EXSLT function element.
 */
public class ElemExsltFuncResult extends ElemVariable {
    static final long    serialVersionUID = -3478311949388304563L;
    /*
     * To keep the binary compatibility put those three private global
     * variables back, although they are never used in this verison
     */
    // A flag indicating whether the return result is set
    private      boolean m_isResultSet    = false;

    // The return result
    private XObject m_result = null;

    // The frame size of the current caller
    private int m_callerFrameSize = 0;

    /**
     * Generate the EXSLT function return value, and assign it to the variable
     * index slot assigned for it in ElemExsltFunction compose().
     */
    public void execute(TransformerImpl transformer) throws TransformerException {
        XPathContext context = transformer.getXPathContext();

        if (transformer.getDebug())
            transformer.getTraceManager().fireTraceEvent(this);

        // Verify that result has not already been set by another result
        // element. Recursion is allowed: intermediate results are cleared
        // in the owner ElemExsltFunction execute().
        if (transformer.currentFuncResultSeen()) {
            throw new TransformerException("An EXSLT function cannot set more than one result!");
        }

        int sourceNode = context.getCurrentNode();

        // Set the return value;
        XObject var = getValue(transformer, sourceNode);
        transformer.popCurrentFuncResult();
        transformer.pushCurrentFuncResult(var);

        if (transformer.getDebug())
            transformer.getTraceManager().fireTraceEndEvent(this);
    }

    /**
     * Get an integer representation of the element type.
     *
     * @return An integer representation of the element, defined in the
     * Constants class.
     * @see wx.xml.xalan.xalan.templates.Constants
     */
    public int getXSLToken() {
        return Constants.EXSLT_ELEMNAME_FUNCRESULT;
    }

    /**
     * Return the node name, defined in the
     * Constants class.
     *
     * @return The node name
     * @see wx.xml.xalan.xalan.templates.Constants
     */
    public String getNodeName() {
        return Constants.EXSLT_ELEMNAME_FUNCRESULT_STRING;
    }
}
